Studies on effect of electrostatic spraying in orchards

Abstract: Evaluation of an electrostatic sprayer (Make ESS, USA) was conducted on a pear orchard planted at 2.5 m row spacing and distance between plant to plant was 1.5 m. The water sensitive paper stripes were placed on each test plant at the upper and underside of the leaves at the different heights of the plant. Effect of charging on droplet density, area covered by droplets, volume of spray deposition, uniformity coefficient and droplet size were observed during the evaluation of the electrostatic sprayer and comparison was made between two different types of nozzle i.e. twin and single nozzle. It was found that droplet density on the upper and under sides of leaves by twin nozzle (Charged) was significantly (p = 0.0005) higher than twin nozzle (Uncharged) by 57.53 % and 59.60 % respectively. Droplet density on the upper and underside of leaves by single nozzle (Charged) was significantly (p = 0.0011) higher than single nozzle (Uncharged) by 58.15 % and 54.65 % respectively. The maximum droplets, i.e. 45 numbers were of size 44 microns observed for the twin nozzle (Charged). But in case of twin nozzle (Uncharged), the maximum droplets, i.e. only 13 numbers of drops were of 44 microns. Similarly maximum droplets, i.e. 32 numbers were of size 44 microns observed for the single nozzle (Charged) and in case of single nozzle (Uncharged), the maximum droplets, i.e. only 11 numbers of drops were of 44 microns. Area covered by droplets on the upper and under sides of leaves by twin nozzle (Charged) was significantly (p = 0.0017) higher than twin nozzle (Uncharged) by 50.19 % and 67.86% respectively. Area covered by droplets on the upper and under sides of leaves by single nozzle (Charged) was significantly (p = 0.0007) higher than single nozzle (Uncharged) by 45.07 % and 67.53 % respectively. Volume of spray deposition on th